With development of sciences and technologies and improvement of people's living standards, requirements for display apparatuses are not only limited to simply transmitting two-dimensional planar information, instead, the display apparatuses are expected to provide three-dimensional image information that is more realistic and stereoscopic, and can achieve more physical and psychological depth clues.
At present, common three-dimensional display apparatuses generally adopt a parallax-type three-dimensional display principle in which left and right views are separated by a cylindrical lens array or a grating array so as to enter left and right eyes of an observer, respectively, thereby producing stereoscopic perception by binocular parallax. However, because such manner can only reflect parallax information, and aggregation and convergence information is difficult to match, the user would experience fatigue, dizziness, nausea and vomiting when viewing above parallax-type naked eye three-dimensional display images for a long time. In addition, the three-dimensional display image presented in this manner does not change as the observer moves his eyes, so that a range of a viewing angle is small and it is difficult to be accepted in the market.
A suspension display technology belongs to a type of integrated imaging, and is a true three-dimensional autostereoscopic display technology based on micro lens array. This technology can achieve the suspension display of an image, increase the viewing angle of the three-dimensional display, and is comfortable to observe without a fatigue, thereby enhancing use experience of the observer. However, in the prior art, for a suspension display apparatus with a definite structure, height of the displayed suspension image is constant, and hence multi-layer displays for the suspension image may not be realized, which in fact limits an application of the suspension display to a certain extent.